Conventionally flush toilets have been known in which, as shown in Patent Document 1 for example, a reservoir tank is provided, and cleaning is accomplished by pressurizing flush water in the reservoir tank using a pressurizing pump and supplying this pressurized water to a toilet main unit.
The flush toilet set forth in this Patent Document 1 is one in which the toilet is cleaned by supplying flush water from a water main source to a rim water path and to a reservoir tank, pressurizing the flush water in the reservoir tank using a pressurizing pump, and supplying a jet-hole.
In addition, a check valve and an atmosphere release valve are provided on the guide path for supplying flush water to the jet-hole in this flush toilet; backflow of flush water from the toilet main unit to the reservoir tank is prevented by this check valve, and air remaining in the water guide path is discharged using an atmosphere released valve, thereby partitioning the toilet main unit and the reservoir tank.
Furthermore, an overflow pipe for conducting flush water overflowing from the reservoir tank is provided on the rim water path in this toilet, and a negative pressure breaker valve is provided on this overflow pipe.
Patent Document: JP-A-2005-264469
In the flush toilet according to Patent Document 1, backflow of flush water from the toilet main unit to the reservoir tank is prevented, and flush water overflowing from the reservoir tank can be discharged externally, but this requires the provision of a check valve, an atmosphere release valve, a negative pressure breaker valve, and the like, leading to a complex structure, an increased number of parts, and other problems. For this reason, further improvements to the flush toilet shown in Patent Document 1 have been desired.